Nonwoven substrates may be useful in a wide variety of applications. Various nonwoven substrates may comprise spunbond-meltblown-spunbond (“SMS”) substrates comprising outer layers of spunbond thermoplastics (e.g., polyolefins) and interior layers of meltblown thermoplastics. Some nonwoven substrates, either in addition to or in place of the meltblown thermoplastics, may comprise fine fibers (i.e., fibers having a diameter of less than one micrometer (“N-fibers”) to create “SMNS” substrates or “SNS” substrates, for example. Such nonwoven substrates may comprise spunbond layers which are durable and internal meltblown layers and/or fine fiber layers which are porous but which may inhibit fast strikethrough of fluids, such as bodily fluids, for example, or the penetration of bacteria through the nonwoven substrates.
Absorbent articles such as diapers, training pants, adult incontinence products, and feminine hygiene products utilize nonwoven substrates for many purposes. For many applications, the barrier properties of the nonwoven substrates play an important role in the performance of the nonwoven substrates, such as the performance as a barrier to fluid penetration, for example. Absorbent articles may comprise multiple elements, such as a liquid pervious material or topsheet intended to be placed next to the wearer's skin, a liquid impervious material or backsheet intended to be placed proximate to or on the outer surface of the absorbent article, various barrier layers or cuffs, and an absorbent core disposed at least partially intermediate the liquid pervious material and the liquid impervious material.
Frequently, films, such as elastomeric films, are used in the manufacturing of various components of absorbent articles and other articles of commerce. For example, films may be used in liquid pervious layers, liquid impervious layers, barrier cuffs, barrier layers, side panels, or in other components of absorbent articles or other articles of commerce. Films provide a high resistance to fluid flow and thus offer ideal barrier performance. This applies even to formed, apertured films where the film area around the apertures provides excellent protection against fluid flow and rewet. Films, however, are quite expensive and less comfortable to a wearer compared to nonwoven substrates. As such, manufacturers of articles of commerce, such as absorbent articles, that incorporate films are usually trying to reduce the amount of the films in their products. What is needed are nonwoven substrates that can match, or come close to matching, the specific advantageous properties of the films, such as low surface tension fluid strikethrough times, while providing comfort to the users and cost advantages to manufacturers. Also, what is needed are nonwoven substrates that have lower basis weights compared to conventional nonwoven substrates, but that have the same fluid strikethrough times as the conventional nonwoven substrates to again save material costs for manufacturers.